Craftsman 5.5 HP B&S interchangeable with Bolens 4.5 HP?

Are all Briggs and Stratton push lawnmower engines interchangeable? I have a Craftsman from the '90s, 917.372.852, 5.5 HP, self propelled in good shape. I have access to an old Bolens, (the guy said just take it away if I want it) with a seized engine. Don't have the Bolens model number but it says plainly on the mower that it was a 4.5 HP. I would like to experiment around with a project using the Bolens mower driven by my Craftsman B&S engine. Can I do that?

Easiest way to find out is to assume it will work and get busy.

The answer to "are all Briggs push lawnmower engines the same" is a definite "no."

Much thanks. I decided to pass it by. If the answer was that all Briggs and Stratton push and self-powered mowers fit up the same, I'd have given it a shot, but I didn't want to add a new project on top of the one time modification project. There seem to be a few running push mowers in the area for not that much money, so I think I'll try that direction.

Yes you can do an engine swap. All those mounting holes are the same from frame to frame. Any engine fits on push mowers.

You would need to take the blade boss off the seized one and put it on your replacement engine.